SIII, also known as elongin, is a general transcription elongation factor that increases the RNA polymerase II transcription elongation past template-encoded arresting sites. Subunit A is transcriptionally active and its transcription activity is strongly enhanced by binding to the dimeric complex of the SIII regulatory subunits B and C (elongin BC complex). Heterotrimer of an A (A1, A2 or A3), B and C subunit. The C subunit mediates the binding of the elongin BC complex to subunit A. Note: This description may include information from UniProtKB.
Protein type: Transcription factor; DNA binding protein
Cellular Component: nucleoplasm; extracellular space; integral to membrane
Molecular Function: DNA binding
Biological Process: transcription from RNA polymerase II promoter; regulation of transcription from RNA polymerase II promoter; viral reproduction; positive regulation of viral transcription; RNA elongation from RNA polymerase II promoter; gene expression
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.